Passive e-paper imaging and erasing

ABSTRACT

An imaging device for a passive e-paper display includes an erasing head to emit ions in a first polarity followed by an opposite second polarity after a first time period. The passive e-paper display is mountable on a support in a spaced apart relationship relative to the erasing head and by which the emitted ions are receivable onto substantially the entire surface of the passive e-paper display. Relative movement occurs between the support and the erasing head at least some of the time during the emission of ions from the erasing head.

CROSS REFERENCE

This application is a Continuation of U.S. patent application Ser. No.15/763,939, filed Mar. 28, 2018, entitled “PASSIVE E-PAPER IMAGING”,which is a U.S. National Stage Application of International ApplicationNo. Application No. PCT/US2015/057774, filed Oct. 28, 2015, entitled“PASSIVE E-PAPER IMAGING”, both of which are incorporated herein byreference.

BACKGROUND

In some instances, electronic (“e-paper”) is described as a displaytechnology designed to recreate the appearance of ink on ordinary paper.Some examples of e-paper reflect light like ordinary paper and may becapable of displaying text and images. Some e-paper is implemented as aflexible, thin sheet, like paper. One familiar e-paper implementationincludes e-readers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagram schematically representing an erasing unit,according to one example of the present disclosure.

FIG. 1B is a block diagram schematically representing a control portion,according to one example of the present disclosure.

FIG. 2A is a top plan view schematically representing a passive e-paperdisplay medium, according to one example of the present disclosure.

FIG. 2B is a sectional view schematically representing a passive e-paperdisplay juxtaposed with an imaging unit, according to one example of thepresent disclosure.

FIG. 3A is a diagram schematically representing different stages of amicrocapsule of a passive e-paper display at different point in timesrelative to a application of ions, according to one example of thepresent disclosure.

FIG. 3B is a diagram schematically representing different stages of amicrocapsule of a passive e-paper display at different point in timesrelative to multiple applications of different polarity ions, accordingto one example of the present disclosure.

FIG. 4 is a diagram schematically representing a state of variousmicrocapsules of a passive e-paper display upon application of ions toerase and write the passive e-paper display, according to one example ofthe present disclosure.

FIG. 5 is a block diagram schematically representing a writing unit,according to one example of the present disclosure.

FIG. 6A is a perspective view schematically representing writing apassive e-paper display by emitting ions via addressable gates,according to one example of the present disclosure.

FIG. 6B is a perspective view schematically representing erasing apassive e-paper display by emitting ions via a corona, according to oneexample of the present disclosure.

FIG. 7A is a diagram schematically representing an imaging device witherasing units separate from a writing unit and by which a passivee-paper display is imaged, according to one example of the presentdisclosure.

FIG. 7B is a diagram schematically representing an imaging device witherasing rollers separate from a writing unit and by which a passivee-paper display is imaged, according to one example of the presentdisclosure.

FIGS. 8A-8C provide a series of diagrams schematically representing animaging device with a multi-use erasing unit separate from a writingunit and by which a passive e-paper display is imaged, according to oneexample of the present disclosure.

FIGS. 9A-9D provide a series of diagrams schematically representing animaging device with a multi-use erasing unit separate from a writingunit and by which a passive e-paper display is imaged, according to oneexample of the present disclosure.

FIGS. 10A-10C provide a series of diagrams schematically representing animaging device with an ion-emitting unit employable in an erasing modeand/or a writing mode, and by which a passive e-paper display is imaged,according to one example of the present disclosure.

FIG. 11A is a block diagram schematically representing a controlportion, according to one example of the present disclosure.

FIG. 11B is a block diagram schematically representing a user interface,according to one example of the present disclosure.

FIG. 12 is a flow diagram schematically representing a method ofmanufacturing an imaging device for a passive e-paper display, accordingto one example of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific examples in which the disclosure may bepracticed. It is to be understood that other examples may be utilizedand structural or logical changes may be made without departing from thescope of the present disclosure. The following detailed description,therefore, is not to be taken in a limiting sense. It is to beunderstood that features of the various examples described herein may becombined, in part or whole, with each other, unless specifically notedotherwise.

At least some examples of the present disclosure are directed to erasingpassive e-paper displays. In some examples, an imaging device for apassive e-paper display includes an erasing unit to emit ions in a firstpolarity followed by an opposite second polarity after a first timeperiod. A support receivably mounts the passive e-paper display in aspaced apart relationship relative to the erasing unit and by which theemitted ions are receivable onto substantially the entire surface of thepassive e-paper display. Relative movement occurs between the supportand the erasing unit at least some of the time during the emission ofions.

In some examples, the support (on which the e-paper display ismountable) is stationary while erasing unit is movable. In someexamples, the erasing unit is stationary while the support is movable.In some examples, both the support and the erasing unit are movable.

In some examples, the erasing unit may emit ions having a positivepolarity or a negative polarity depending on a particular erasingprotocol. In one example erasing protocol, in a first relative movementbetween the e-paper display relative to the erasing unit, a firstblanket of one polarity of ions (e.g. positive) are applied tosubstantially an entire surface of the e-paper display. This first passis followed by a second relative movement (e.g. a second pass) in whicha second blanket of another polarity ions (e.g. negative) is applied tosubstantially an entire surface of the e-paper display. However, in someexamples, the erasing unit may apply the ions in a different order ofpolarity, such as a first application of negative ions followed by asecond application of positive ions. In addition, in some examples morethan two “erasing” applications of ions may be implemented oversubstantially the entire surface of the e-paper display.

By making at least two applications of different polarity ions, theerasing unit may facilitate achieving a generally uniform appearance(e.g. all white, all black, all neutral, etc.) of the e-paper displayprior to writing a new image to the e-paper display. In one aspect, thisarrangement increases clarity of the new image by removing any potentialresidue of a prior image that might otherwise have remained in theabsence of multiple “erasing” applications of ions onto e-paper displayprior to writing the new image.

These examples, and additional examples, are described and illustratedbelow in association with at least FIGS. 1A-12.

FIG. 1A is diagram schematically representing a device 20 including anerasing unit 22, according to one example of the present disclosure. Insome examples, erasing unit 22 is positionable to selectively emit ions27 or ions 28 onto a spaced apart passive e-paper display 31. In someexamples, e-paper display 31 is receivably mountable on a support 33,which is spaced apart from an ion-emitting surface 25 in a manner tocause the e-paper display 31 to be spaced apart from the ion-emittingsurface 25 by a distance D1.

As shown in FIG. 1A, passive e-paper display 31 includes a generallyplanar member having opposite surfaces 38, 39 (e.g. faces). In someexamples, one of the surfaces 38, 39 of passive e-paper display 31corresponds to an image-writing surface of the e-paper display 31 andone of those respective surfaces 38, 39 corresponds to an image-viewingsurface of the e-paper display 31. In some examples, the image-viewablesurface (i.e. image-bearing surface) corresponds to the image-writingsurface of the e-paper display 31 while in some examples, theimage-viewable surface (i.e. image-bearing surface) corresponds to anon-image-writable surface of the e-paper display 31. Further details ofthese relationships are described later in association with at leastFIG. 2B.

In some examples, erasing unit 22 may emit ions 27 having a positivecharge 24 or a negative charge 26, according to an erasing protocol. Inone example erasing protocol, in a first relative movement (e.g. a firstpass) between the e-paper display 31 relative to erasing unit 22, afirst blanket of one polarity of ions (e.g. positive) are applied tosubstantially an entire surface (e.g. 38) of the e-paper display 31.This first pass is followed by a second relative movement (e.g. a secondpass) in which a second blanket of opposite polarity ions (e.g.negative) is applied to substantially an entire surface (e.g. 38) of thee-paper display 31. However, in some examples, erasing unit 22 may applythe ions in a different order of polarity, such as a first applicationof negative ions followed by a second application of positive ions.

In some cases, erasing unit 24 emits positive ions 27 or negative ions28 to have a particular distribution of the blanket charges in thedirection of the card movement influencing the erase waveform to enhanceerasure by taking into account, at least, the particles charge at highand low field, interaction with free charges, binder conductivity, etc.

By making at least two applications of different polarity ions, erasingunit 22 may facilitate achieving a generally uniform appearance (e.g.all white or all black, etc.) of the e-paper display 31 prior to writinga new image to the e-paper display 31. In one aspect, this arrangementincreases clarity of the new image by removing any potential residue ofa prior image that might otherwise remain in the absence of multiple“erasing” applications of different polarity ions onto e-paper display31 prior to writing the new image.

In some examples, the application of ions from erasing unit 22 can bemade over less than substantially entire surface of the e-paper display31.

In some examples, device 20 includes a separate writing unit in additionto the erasing unit 22, as later described in association with at leastFIGS. 7A-9. In some examples, erasing unit 22 is equipped in a mannersuch that it also may be employed as a writing unit, as later describedin association with at least FIG. 10.

In some examples, during such relative movement the support 33 isstationary while erasing unit 22 is movable. In some examples, duringsuch relative movement the erasing unit 22 is stationary while thesupport 33 is movable. In some examples, during such relative movementboth the support 33 and erasing unit 22 are movable.

FIG. 1B is a block diagram schematically representing a control portion35, according to one example of the present disclosure. In someexamples, control portion 35 comprises at least some of substantiallythe same features and attributes as control portion 660, as laterdescribed in association with at least FIG. 11. In some examples,control portion 35 forms part of, or operates in association with,control portion 660. In some examples, control portion 35 facilitatescontrol over the sequence and timing by which ions are emitted fromerasing unit 22, as well as facilitating control over a velocity (e.g.both speed and direction) of relative movement between support 33 anderasing unit 22.

FIG. 2A is a top plan view of a display medium 34 including a passivee-paper display 31, according to an example of the present disclosure.In some examples, e-paper display 31 comprises at least some ofsubstantially the same features and attributes as passive e-paperdisplay 31, as previously described in association with FIG. 1A.

As further shown in FIG. 2A, in some examples e-paper display 31 bearsan image 40 expressed across substantially the entire available viewingsurface 38. In some examples, image 40 includes portions 42 (“RetailerBrand Name”), 44 (“Product Name”), 46 (“Product Details”), and/or 48 (QRCode graphic). Accordingly, image 40 comprises text and/or graphics. Itwill be understood that in this context, in some examples, graphics alsorefers to an image, such as specific picture of a person, object, place,etc. Moreover, the particular content of the information in image 40 isnot fixed, but is changeable by virtue of the rewritable nature of thee-paper display 31. In one example, a location, shape, size of portions42, 44, 46, 48 of an image 40 is also not fixed, but is changeable byvirtue of the rewritable nature of the e-paper display 31.

As shown in FIG. 2A, in some examples, display medium 34 includes asupport frame 32 secured to a portion of e-paper display 31. In someexamples, frame 32 defines a generally rectangular member, as shown inFIG. 2A, which generally matches the size and shape of the periphery ofthe e-paper display 31. In some examples, the frame 32 is generallyco-extensive with an outer portion of the e-paper display 31. In someexamples, frame 32 is omitted and e-paper display 31 is free-standingwithout frame 32.

In some examples, frame 32 is made from a polycarbonate orpolyvinylchloride (PVC) material. However, in more general terms, frame32 is made from a resilient or semi-rigid material that is generallynon-conductive and that provides mechanical strength and toughness tothe e-paper display 31 for protection from bending, compression,abrasion, etc.

In at least some examples of the present disclosure, in addition to thechangeable content available via e-paper display 31, fixed content 51may be located on the frame 32. In some examples, the fixed content 51may include a logo, name or indicia. In some examples, the fixed content51 may relate to a retailer or other entity associated with the contentwritable onto the e-paper display 31. In some examples where employment,access, and/or security related information is imaged onto e-paperdisplay 31, the fixed content 51 may include a logo, name, or indicia ofa company, employer, government entity, etc. In some examples, the fixedcontent 31 is imaged via inkjet printheads, digital press, etc. usinginks, toners, etc. that would typically be used to print on paper,plastic.

In general terms, display medium 34 includes any visual medium ofcontent consumption. In some examples, display medium 34 includesfinancial transaction media (e.g. gift cards, prepaid cards, insurancecards, credit cards, etc.) or information transaction media (e.g. shelftags, boarding passes, shipping labels, package tracking in general. Insome examples, display medium 34 includes media used to gain access,establish credentials, and/or implement security.

In at least some examples of the present disclosure, e-paper display 31is passive in the sense that it is re-writable and holds an imagewithout being connected to an active power source during the writingprocess and/or after the writing is completed. Accordingly, in someexamples, e-paper display 31 omits an on-board power source. In someexamples, the e-paper display 31 omits internal circuitry or internalelectrode arrays that might otherwise be associated producing specificimages in the e-paper display 31. Instead, in some examples, the passivee-paper display 31 relies on a charge-responsive layer that is imageablevia an external writing module.

Instead, as further described later, the passive e-paper display 31 isimaged in a non-contact manner in which the e-paper display 31 receivescharges (emitted by a ion head) that travel through the air and thenform image 40 via a response by charged particles within a layer of thee-paper display 31. After the imaging process is completed, the passivee-paper display 31 retains the image generally indefinitely and withouta power supply until image 40 is selectively changed at a later time.

In at least some examples, the passive e-paper display 31 operatesconsistent with electrophoretic principles. With this in mind, in atleast some examples, passive e-paper display 31 includes acharge-responsive layer in which charged color particles switch colorwhen charges are selectively applied a non-contact manner (e.g. airbornemigration) by an external module spaced apart from the charge-responsivelayer. In some examples, the charged color particles comprisepigment/dye components. In one aspect, this arrangement is implementedvia microcapsules containing a dispersion of pigmented particles in adielectric oil. In some examples, a resin/polymer forms a matrixmaterial that retains the microcapsules in the charge-responsive layer.

In one example, the passive e-paper display 31 further includes aconductive layer which serves as a counter-electrode on one side of thee-paper display 31. In some examples, an additional functional coatingis applied to an imaging side of the e-paper 31.

One implementation of an e-paper display 31 according to above-describedexamples of the present disclosure is later described and illustrated inassociation with at least FIG. 2B.

FIG. 2B is a sectional view providing a schematic representation of ane-paper display 131 and an associated e-paper writing system 100,according to one example of the present disclosure. In some examples,this e-paper display 131 is implemented via an e-paper structure 100having at least some of substantially the same features and attributesas e-paper display media previously described in association with atleast FIGS. 1A and 2A, and in subsequent examples described inassociation with at least FIGS. 3A-10. Meanwhile, writing system 100includes an imaging module 102 and is provided in FIG. 2B to generallyillustrate a response of the e-paper structure 101 (of e-paper displaymedia 131) to an erasing modality 106 and/or writing modality 104.

As shown in FIG. 2B, imaging module 102 includes writing modality 104and erasing modality 106. In some examples, the erasing modality 106 isimplemented via an ion-emitting element separate from, and independentof, a different ion-emitting element which implements the writingmodality 104. In some such examples, the erasing modality 106 isimplemented via a plurality of ion-emitting elements with each producinga particular polarity ion opposite than other respective ion-emittingelements. One instance is later described in association with at leastFIG. 7.

In some examples, the erasing modality 106 is implemented via a singleion-emitting element for which the polarity of the ions-to-be-emittedcan be selectively switched between positive and negative. One instanceis later described in association with at least FIGS. 8A-8C and 9A-9D.

In some examples, the writing modality 104 and erasing modality 106 areimplemented via the same ion-emitting element, and by which a polarityof the ions-to-be-emitted can be selectively switched between positiveand negative. One instance is later described in association with atleast FIG. 10.

In some examples, one or both of the writing modality 104 and erasingmodality 106 comprises a corona-based charge ejecting device.

In some examples, instead of employing an ion-based emitting head,erasing modality 106 is implemented via an electrode that comes intoclose contact with, rolls across, or that is dragged along, the surface108 in front of a separate writing modality 104. One such example islater described in association with at least FIG. 7B.

In some examples, e-paper structure 101 has an imaging surface 38 and anopposite non-imaging surface 39, as in FIGS. 1A and 2A.

In general terms, e-paper structure 101 includes a protective layer 108,a charge-responsive layer 109, and a base 110. The protective layer 108is sometimes referred to as charge-receiving layer 108. The base 110defines or includes a counter electrode, as further described below,which serves as a ground plane.

In some examples, the base 110 is opaque, such that the imaging surface38 also defines a viewing side of e-paper display media 160, asrepresented via eye icon 22 and reference V1. However, in some examplesthe base 110 is at least translucent or transparent, such thatnon-imaging surface 39 defines the viewing side of e-paper display media160, as represented via eye icon 22 and reference V2 shown in FIG. 4A.

In the example shown in FIG. 2B, the charge-responsive layer 109includes a plurality of microcapsules 105 disposed within a matrixmaterial 131 and with each microcapsule 105 encapsulating some chargedblack particles 124 and some charged white particles 120 dispersedwithin a dielectric liquid, such as an oil. In one example, as shown inat least FIG. 2B, the black particles 124 are positively charged and thewhite particles 120 are negatively charged.

In some examples, microparticles 120 have a color other than white andmicroparticles 124 have a color other than black, provided thatmicroparticles 120 have a color different than microparticles 124. Insome examples, the color of the particles is originated from pigments,while in some examples the color originates from a dye.

In some examples, charge-responsive layer 109 is formed withmicrocapsules 105 containing just charged particles 120 (and notcontaining any charged particles 124) suspended within the microcapsules105 with an electrically neutral dye having a color different than thecolor of the particles 120 (e.g. white in one example). In someexamples, the liquid solution is dielectric. In some instances, suchdielectric solutions include isoparaffinic fluids, such as an Isopar®fluid. Likewise, in some examples, charge-responsive layer 109 is formedwith microcapsules 105 containing just charged particles 124 (and notcontaining any charged particles 120) suspended within the microcapsules105 with an electrically neutral dye having a color different than thecolor of the particles 124 (e.g. black in one example).

In some examples, via the erasing modality 106, any information storedvia the microcapsules 105 is removed prior to writing information viawriting modality 104. In the example shown in FIG. 2B, as the e-paperstructure 101 passes under the imaging module 102, the erasing modality106 emits positive ions 107, which act to remove negative ions that areattached to the surface 108. The positive charge erasing modality 106also creates electrostatic forces, which drive positively charged blackparticles 124 away from the charge receiving layer 108 and which attractnegatively charged white particles 120 toward the charge receiving layer108. By passing the erasing modality 106 over the charge receiving layer108, the information written to the e-paper structure 101 is erased bypositioning the negatively charged white particles 120 near the top ofthe microcapsules 105 and pushing the positively charged black particles124 to the bottom of the microcapsules 105.

During writing, electrical contact is made by a ground resource withexposed portions of base 110 (including a counter electrode) to allowbiasing of the writing modality 104 while it applies charges to chargereceiving layer 108 during the writing process.

Microcapsules 105 exhibit image stability via chemical adhesion betweenmicroparticles and/or between the particles and the microcapsulesurface. For example, microcapsules 105 can hold text, graphics, andimages indefinitely without using electricity, while allowing the text,graphics, or images to be changed later.

The structure, materials, and dimensions of the various layers andcomponents of e-paper structure 101 are chosen for specific designcriteria. In one example, the transparent charge receiving layer 108 iscomposed of a transparent polymer and can have a thickness between 50 μmand 250 μm. In some examples, the transparent charge receiving layer 108is also composed of a material that holds charges or is porous orsemi-porous to charges and/or ions.

In some examples, the diameter of each microcapsule 105 is substantiallyconstant within charge-responsive layer 109 of e-paper structure 101and, in some examples, the thickness of charge-responsive layer 109 isbetween about 20 μm and about 100 μm, such as 50 μm. In some examples,base 110 has a thickness between about 20 μm and about 1 mm, or largerdepending on how e-paper display 131 is to be used. In some examples,the protective or charge-receiving layer 108 is about 5 microns thick.

In one aspect, base 110 is structured to provide enough conductivity toenable counter charges to flow during printing. As such, in generalterms, base 110 comprises a member including at least some conductiveproperties. In some examples, base 110 comprises a non-conductivematerial that is impregnated with conductive additive materials, such ascarbon nanofibers or other conductive elements. In some examples, base110 comprises a conductive polymer, such as a urethane material or acarbonite material. In further examples, base 110 is made from aconductive polymer with carbon nanofibers, to provide flexibility withadequate strength.

In some examples, base 110 is primarily comprised of a conductivematerial, such as an aluminum material and therefore is impregnated orcoated with additional conductive materials.

In some examples, whether conductivity is provided via coating,impregnation or other mechanisms, the body of base 110 is formed from agenerally electrically insulative, biaxially-oriented polyethyleneterephthalate (BOPET), commonly sold under the trade name MYLAR, toprovide flexibility and strength in a relatively thin layer.

In some examples, the base 110 is opaque or is transparent, depending onthe particular implementation of the e-paper display medium. Withfurther reference to FIG. 2B, in some examples, base 110 is opaque, suchthat image-writing surface 38 of e-paper display 31 also serves as animage-viewing surface, as represented via eye icon 52 and reference V1in FIG. 2B. However, in some examples, base 110 is provided as atransparent element, such that the bottom surface 39 of e-paper display31 serves as an image-viewing surface of the e-paper display 131 asrepresented via eye icon 52 and reference V2 in FIG. 2B. In someexamples, in this latter arrangement, layer 125 is opaque.

In some examples, the base 110 comprises a generally resilient material,exhibiting flexibility and in some implementations, semi-rigid behavior.In some examples, the base 110 comprises a rigid material.

In some examples, the protective, charge receiving layer 108 is madefrom a semi-conductive polymer having a resistivity of about 10⁹ Ohm-cmor a porous layer that enables ion charges to pass through the layer 108during erasing and/or writing cycles.

FIG. 2B also shows one example writing operation performed by thewriting modality 104 in which the deposition of charges influences thedistribution of charged pigments/particles within affected microcapsules105. In one aspect, the writing modality 104 is designed and operated toselectively eject electrons 114, shown as black bars, toward the chargereceiving surface 108, when a region of the e-paper structure 101located beneath the writing modality 104. As the electrons 114 reach thesurface 108, the negatively charged white particles 120 are repelled anddriven away from the charge receiving surface 108, while the positivelycharged black particles 124 are attracted to the negatively chargedelectrons/ions 114 and driven toward the charge receiving surface 108.Areas of charge-receiving layer 108 will retain a positive charge, andtherefore a white appearance in this example.

Furthermore, as the writing modality 104 passes over microcapsules 105while ejecting electrons, the negatively charged white particles 120 arerepelled away from the insulating layer and the positively charged blackparticles 124 are driven toward the charge receiving layer 108.

In some cases, charges 116 gradually decline after generating the image40.

The e-paper writing system 100, as shown in FIG. 2B, is not limited toimplementations in which the writing modality 104 discharges electronsand the erasing modality 106 erases information with positive charges.Instead, in some examples, the microcapsules 105 in matrix material 131of the charge-responsive layer 109 of e-paper structure 101 are composedof negatively charged black particles 124 and positively charged whiteparticles 120. In such examples, the writing modality 104 is designed toproduce positive ions for forming a new image, while the erasingmodality 106 uses negative charges to erase prior imagery from passivee-paper display 131.

In some examples, charge receiving layer 108 comprises a protectiveelement or coating, which protects the charge-responsive layer 109(including microcapsules 105) from mechanical damage, pressure andimpact, and from collecting tribo charges. It also is designed to reduceincreases in dot size due to field screening during charging (the“blooming effect”). In one implementation, the protectivecharge-receiving layer 108 includes semiconducting characteristics whichallow for a controlled decay of the latent charge image, such that thelayer 108 gradually dissipates the charges to the ground defined by base110. The resistivity of the layer 108 is designed to enable fastmovement of charges through layer 108. In some instances, the chargeswill be transferred to ground at least partially defined by base 110through the layer 109. In particular, the matrix material 131 ofcharge-responsive layer 109 is selected to provide the desired opticaland mechanical characteristics, as well as the desired electricalresistivity.

It will be understood that in some examples, erasing modality 106 inFIG. 2B acts as a general schematic representation of a plurality oferasing units, each emitting ions of a different polarity. One exampleimplementation of such an erasing modality 106 is described inassociation with FIGS. 4A and 7A.

In some examples, the erasing of one surface 125 of passive e-paperdisplay 131 is performed without heating during (or before) ions areemitted onto and received by surface 125. Moreover, in some examples,the matrix material 131 in which microcapsules reside and/or anysubstances in which microparticles 120, 124 are suspended within eachmicrocapsule omits (i.e. does not include) a thermo-reversible gel.Accordingly, the switching of color microparticles toward or awaysurface 125 of passive e-paper display 131 occurs without the aid of athermo-reversible gel.

FIG. 3A is a diagram 140 schematically representing different stages ofa microcapsule 105 of a passive e-paper display relative to anapplication of negative ions 142, according to one example of thepresent disclosure.

In this particular example, the black microparticles 124 are negativelycharged and the white microparticles 120 are positively charged. Thefirst stage in FIG. 3A corresponds to a microcapsule 105 presenting apartially black, partially appearance at surface 144 as seen by a viewer52. The second stage corresponds to the application of negative ions 142via an erasing unit, such as erasing unit 22 in FIG. 1A, erasingmodality 106 (FIG. 2B), or one of the other erasing units/modalities aslater described in association with at least FIGS. 4, 7A-10.

In the second stage, the negative ions 142 at the surface 144 of themicrocapsule 105, repel or drive the negatively charged blackmicroparticles 124 toward the other side 145 of the microcapsule 105 (asrepresented by arrow A) while attracting the positively charged whitemicroparticles 120 to migrate toward the negative ions 142 at surface144, as represented by arrow B. This process may continue until all ofthe positively charged white microparticles 120 have migrated to thefirst surface 144 of microcapsule 105 and all of the negatively chargedblack microparticles 124 have migrated to the second surface 145 ofmicrocapsule.

However, in some instances, at least some of the microparticles (120,124) that should migrate to an opposite side of a microcapsule 105remain in place. For instance, the third stage in FIG. 3A corresponds tothis situation in which at least some microparticles (e.g. at least oneblack microparticle 126) did not migrate to the opposite surface 145 ofmicrocapsule 105, thereby preventing surface 125 (of e-paper display131) from having a generally uniform or blank appearance as one wouldintend or expect from an erasing action. In some instances, thismicroparticle 126 fails to migrate the mechanical and/or chemicaladhesion forces between the microparticle 126 and the interiorenvironment of the microcapsules 105 are stronger than the electricalforces exerted by ions 142 at surface 125 of the e-paper display 131. Insome instances, such stray microparticles 126 tend to be smaller in sizethan other microparticles, with such smaller microparticles exhibitingstronger mechanical and chemical adhesive forces and exhibiting smallerelectrical charges due to their smaller surface areas. Consequently,such microparticles 126 may inhibit a thorough erasing of surface 125 ofe-paper display 131.

FIG. 3B is a diagram schematically representing different stages of amicrocapsule of a passive e-paper display 131 relative to multipleapplications of different polarity ions, according to one example of thepresent disclosure. The first stage in FIG. 3B corresponds to the firststage shown in FIG. 3A. However, prior to application of negative ionsto erase the microcapsule 105 (as in second stage of FIG. 3A), in someexamples positive ions 152 are applied to microcapsule 105 to causemigration of negatively charged black microparticles 124 to surface 145and of positively charged white microparticles 120 to surface 144, asrepresented in second stage of FIG. 3B. When complete, this initialerasing action gives the microcapsules 105, and consequently one surface125 of an entire e-paper display 131, a generally uniform blackappearance as shown in the third stage in FIG. 3B. In one aspect, ions152 shown in the second stage in FIG. 3B are applied via an erasing unitor modality, such as those previously described.

In addition, by driving all of the black microparticles 124 to surface144 as shown in the third stage, the black microparticles 124 becomeenmeshed and chemically/mechanically adhered relative to any potentiallystray microparticles 126. Accordingly, upon a second application of ions162 (e.g. negative ions) to the surface 125 of the e-paper display 131as shown in the fourth stage in FIG. 3B, all of the black microparticles124 are driven away from surface 144 of microcapsule 105 to oppositesurface 145. Meanwhile, the second application of ions 162 attracts thepositively charged white microparticles 120 to surface 144, therebyproducing a generally uniformly white or blank appearance at surface 125of e-paper display 131 as shown in the fifth stage of FIG. 3B.

Accordingly, via this double erasing action, the surface 125 of thee-paper display 131 is deemed to be erased, i.e. made blank via thegenerally uniform appearance of one color of microparticles (e.g. 120).At least some examples of the present disclosure achieve thisarrangement via at least two applications of different polarity ions inwhich a first application is made with first polarity ions and a secondapplication is made with second opposite polarity ions.

FIG. 4 is a diagram 200 schematically representing a state of variousmicrocapsules of a passive e-paper display 231 upon an imaging device210 applying ions to erase and write to the passive e-paper display 231,according to one example of the present disclosure. In some examples,e-paper display 231 comprises at least some of substantially the samefeatures and attributes as e-paper display 131 in FIGS. 2B-3B.

In some examples, the imaging device 210 includes a first erasing unit211, a second erasing unit 212, and a writing unit 214. In this example,within each microcapsule 105, the black microparticles 124 arenegatively charged and the white microparticles 120 are positivelycharged. Accordingly, as relative movement between e-paper display 231and imaging device 210 occurs (as represented by directional arrow X1),the first erasing unit 211 emits positive ions 217 to produce a layer ofpositive ions 218 at receiving surface 125 of e-paper display 231. Thesesurface charges 218, in turn, draw negatively charged blackmicroparticles 124 to surface 125 to help create a generally uniformlyblack appearance at surface 125, while also facilitating at leasttemporary adhesion of the black microparticles 124 relative to eachother.

As further shown in FIG. 4, portion 220 represents the gradualdissipation over time of positive charges 218 at surface 125, asrepresented by the smaller and/or lighter plus symbols (+) spanning fromright to left as e-paper display 231 travels from right to left in FIG.4. In some examples, the distance D2 between the first erasing unit 211and the second erasing unit 212 depends on several factors. One factorincludes a velocity during relative movement of the passive e-paperdisplay 231 relative to the erasing units 211 and 212, which in turndetermines a time period (e.g. elapsed time) between when ions 217emitted from erasing unit 211 contact e-paper display 131 and when ions231 emitted from erasing unit 212 contact e-paper display 131. Anotherfactor influencing determination of distance D2 includes the speed atwhich electrophoretic movement of the black microparticles 124 occurs,which therefore affects the total time for all of the blackmicroparticles 124 to migrate to the other surface 145 of themicrocapsules 105. Another factor by which distance D2 is determinedincludes the amount of time to achieve a desired level of dissipation ofcharges 218 at surface 125. In one aspect, positive charges 218dissipate from surface 125 as they flow to the counter electrode (e.g.at base 110 in FIG. 2B) located on the other side of the microcapsules105. The flow time, in turn, depends at least on the resistivity of thelayer of microcapsules 105 and the resistivity of the charge-receivinglayer 108 (FIG. 2B).

In some examples, erasing unit 211 and erasing unit 212 share the samecollector electrical potential, i.e. have the same ground. In someexamples, erasing unit 211 and erasing unit 212 each have their own,different collector potential. In these latter examples, selection ofdistance D2 also is at least partially determined according to a lengthof the e-paper display 131, wherein the length is measured in thedirection of travel (e.g. X1) of the e-paper display 131.

In some examples, first erasing units 211 and second erasing units 212include a corona (216, 231 respectively) to generate and emit ions (217,231 respectively), as shown schematically in FIG. 4. However, it will beunderstood that in some examples, first and second erasing units 211,212 may include ion-generating modalities other than a corona.

With continued reference to FIG. 4, as further relative movement betweene-paper display 231 and imaging device 210 occurs (as represented bydirectional arrow X1), the first erasing unit 212 applies negative ions232 to produce a layer of negative charges 233 at receiving surface 125of e-paper display 231. These negative charges 233, in turn, drawpositively charged white microparticles 120 to surface 125 while pushingaway negatively charged black microparticles 124 to thereby produce agenerally uniformly white or neutral appearance at surface 125. In oneaspect, because the negatively charged black microparticles 124 wereaggregated together per action of first erasing unit 211, then they tendto move together upon action of second erasing unit 212 with theelectric adhesive forces among black microparticles 124 overcomingchemical/mechanical adhesive forces (to which some individualmicroparticles 124 might be subject), thereby minimizing or eliminatingthe phenomenon of undesired stray microparticles (e.g. 126 in FIG. 3A)staying at surface 125.

As further shown in FIG. 4, portion 235 represents the gradualdissipation of negative charges at surface 125 which occurs over time,as represented by smaller and/or lighter plus symbols (+) as e-paperdisplay 231 moves from right to left in FIG. 4.

In some examples, the distance D3 between the second erasing unit 212and the writing unit 214 depends on several factors. One factor includesa velocity during relative movement of the passive e-paper display 231relative to the erasing unit 212 and writing unit 214, which in turndetermines a time period (e.g. elapsed time) between when ions 231emitted from erasing unit 212 contact e-paper display 131 and when ions240 emitted from writing unit 214 contact e-paper display 131. Anotherfactor influencing determination of distance D3 includes the speed atwhich electrophoretic movement of the white microparticles 124 occurs,which therefore affects the total time for all of the whitemicroparticles 120 to migrate to the other surface of the microcapsules105. Another factor by which distance D3 is determined includes theamount of time to achieve a desired level of dissipation of charges 233at surface 125. In one aspect, negative charges 233 dissipate fromsurface 125 as they flow to the counter electrode (e.g. at base 110 inFIG. 2B) located on the other side (e.g. 145) of the microcapsules 105according to a collector potential. The flow time, in turn, depends atleast on the resistivity of the layer of microcapsules 105 and theresistivity of the charge-receiving layer 108.

In some examples, erasing unit 212 and writing unit 214 share the samecollector potential. In some examples, erasing unit 212 and writing unit214 each have their own, different collector potential. In these latterexamples, then selection of distance D3 also is at least partiallydetermined according to a length of the e-paper display 131, wherein thelength is measured in the direction of travel of the e-paper display131.

In some examples, a speed of electrophoretic movement of the blackmicroparticles 124 is three times faster than a speed of electrophoreticmovement of the white microparticles 120, and therefore a distance D2may be less than distance D3 because less time may be involved forcharges 218 to dissipate from surface 125.

As further shown in FIG. 4, after charges 233 have substantiallydissipated at surface 125, positive ions 240 emitted by writing unit 214form a pattern 236 corresponding to an image (e.g. 40 in FIG. 2A) onsurface 125 of e-paper display 231, thereby causing migration of blackmicroparticles 124 to appropriate areas of the surface 125, and theassociated driving of white microparticles 120 away from surface 125.

In some examples, the application of ions via the first erasing unit 211need not cause a complete migration of all black microparticles 124 tosurface 125. Rather, in some instances, the amount of ions (based ontime, intensity, and distance) emitted by first erasing unit 211 ispurposed to cause at least a threshold percentage of microparticles(e.g. black microparticles 124) to migrate to surface 125. In oneaspect, the threshold percentage corresponds to a relative volume ofmicroparticles which are sufficient to remove or prevent straymicroparticles (e.g. 126 in FIG. 3A) without necessarily involving themigration of all microparticles 124 to surface 125. In some instances,performing erasure according to a threshold percentage may enableapplying ions from first erasing unit 211 for a shorter period of time,and also consequently reduce the distance D2 between first erasing unit211 and second erasing unit 212, because it will take less time formigration of the threshold percentage of microparticles (as compared tomigration of all black microparticles). In some examples, the thresholdpercentage falls within a range of 50 to 99 percent of all blackmicroparticles. In some examples, the threshold percentage is at least60 percent. In some examples, the threshold percentage is at least 70percent. In some examples, the threshold percentage is at least 80percent.

In some examples, to the extent that first erasing unit 211 may beoperated in association with such a threshold percentage, then seconderasing unit 211 may be operated for a shorter period of time and/orless intensity to produce the generally uniform appearance of white orneutral microparticles 120 prior to operation of writing unit 214. Inthis way, the imaging module 210 can “erase” the e-paper display 131faster than in some previously described examples, in which all blackmicroparticles 124 are brought to surface 125.

FIG. 5 is a block diagram schematically representing a writing unit 250,according to one example of the present disclosure. In some examples,writing unit 250 provides just one example of the writing unit 214 inFIG. 4 and/or one of the writing units described in association with atleast FIGS. 7A-10. As shown in FIG. 5, writing unit 250 includes ahousing 252 to arrange an ion generating unit 260 and addressable gates262. In some examples, the ion generating unit 260 comprises a corona,while in some examples, the ion generating unit 260 comprises othermodalities for generating ions. In some examples, ion generating unit260 includes multiple, separate ion generating elements.

In some examples, ions generated via unit 260 engage a plurality ofaddressable gates 262, which permit ions to exit surface 253 of housing252 according to which gates 262 are selectively activated. In someexamples, each gate 262 may take the form of a hole or a nozzlestructure, which can be electrically closed or opened based onselectable relative voltages of an associated electrode structure whichexerts an electric field at the gate. An open gate permits passage ofions while a closed gate prevents passage of ions.

In some examples, ions are generated specific to each addressable gatewhile in some examples, ions are generated generally (such via a singleion generating unit) for use with any of the addressable gates.

In some examples, writing unit 252 is implemented with at least some ofsubstantially the same features and attributes as in PCT Publication WO2015/116226, published on Aug. 6, 2015 under title E-PAPER IMAGING VIAADDRESSABLE ELECTRODE ARRAY.

Accordingly, in one aspect, FIG. 5 schematically represents the emissionof groups of ions (264A, 264B, 264C) in a selected pattern in order toform a desired image on an e-paper display 231.

In some examples, the plurality of gates 262 has a width (W1) to emitions in a span up to an entire width of a passive e-paper display 131,as further shown in FIG. 5. One implementation of the addressable gates262 is schematically represented in FIG. 6A in which set 282 of gates283 is sized and shaped to span at least a width of the e-paper display131, and as such may be referred to as a page wide set 282 ofaddressable gates 283. As represented by arrow X1, relative movementbetween the set 282 of gates 283 and e-paper display 131 will result inapplication of ions in a selectable pattern according to which gates 283are activated (i.e. open) at any given point in time.

In some examples, a substantial percentage of, or all of, the gates 283can be opened to permit the passage of ions such that the set 282 ofaddressable gates 283 applies a blanket of ions to at leastsubstantially the entire surface of the e-paper display 131. In suchimplementations, the set 282 of addressable gates 283 can mimic thebehavior of a general ion-emitter (e.g. corona or other modality) notcapable of emitting selective patterns of ions. Accordingly, someimplementations of a writing unit 250 with a set 282 of addressablegates 283 also may act as an erasing unit, such as later described inassociation with at least FIG. 10.

FIG. 6B is a diagram including a perspective view schematicallyrepresenting erasure of a passive e-paper display 131 by emitting ionsvia an ion generating unit 292, according to one example of the presentdisclosure. As shown in FIG. 6B, ion generating unit 292 includes acorona arranged with its length generally transverse to a direction(arrow X1) of relative movement between the corona and the e-paperdisplay 131. In one aspect, a length of the corona generally matches thewidth (W2) of the e-paper display 131. Upon activation, the coronaproduces ions along its length, thereby forming a blanket 293 of ionswhich become applied to the e-paper display 131. Upon emitting theblanket 293 of ions for an appropriate amount of time, and assuming anappropriate velocity of relative movement (arrow C1), the blanket 293 ofions may induce the e-paper display 131 to exhibit a generally uniformappearance of one color of microparticles (e.g. either neutral or black,depending on their respective charge) at surface 125.

Accordingly, in some examples, ion generating unit 292 may function asan erasing unit as described elsewhere in the present disclosure, suchas erasing unit 22 (FIG. 1A), erasing units 211, 212 (FIGS. 4, 7A),and/or erasing unit 412 (FIGS. 8A-8C and 9A-9D).

FIG. 7A is a diagram 310 schematically representing an imaging device210 with erasing units 211, 212 separate from a writing unit 214 and bywhich a passive e-paper display 131 is imaged, according to one exampleof the present disclosure. In some examples, the imaging device 210generally corresponds to the imaging device 210 as shown and describedin association with FIG. 4, except with FIG. 7A further depicting thespatial relationships among erasing units 211, 212, writing unit 214,and e-paper display 131. Accordingly, FIG. 7A further depicts a pair ofconveying structures 310A, 310B for conveying e-paper display 131relative to the erasing units 211, 212 and writing unit 214. In someexamples, each conveying structure 310A, 310B comprises a movableelement, such as belt or chain of linked elements.

Consistent with the behavior previously described and illustrated inassociation with at least FIGS. 3B-4, the double erasing action ofdifferent polarity erasing units 211, 212 produces a generally uniformappearance at surface 125 of e-paper display 131 prior to a writing unit(e.g. 214 in FIG. 4) writing a new image on e-paper display 131.

FIG. 7B is a diagram 350 schematically representing an imaging device360 with erasing elements 362, 364 separate from a writing unit 214 andby which a passive e-paper display 131 is imaged, according to oneexample of the present disclosure. In some examples, imaging device 360comprises at least some of substantially the same features andattributes as imaging device (FIG. 7A), except including contact-based,conductive erasing elements 362, 364 instead of contact-less,ion-emitting erasing units 211, 212. In some examples, thecontact-based, conductive erasing elements 362, 364 comprise rollers, asshown in FIG. 7B.

In a manner similar to the example of FIG. 7A, erasing elements 362 and364 are operated with opposite polarities. Accordingly, in someexamples, erasing element 362 exhibits a positive polarity and erasingelement 364 exhibits a negative polarity while in some examples, erasingelement 362 exhibits a negative polarity while erasing element 364exhibits a positive polarity.

In one aspect, the erasing elements 362, 364 are spaced apart by adistance D4, which may or may not be the same as distance D2 in FIG. 7A,as the erasing element 362 may deliver charges to the surface 125 of thee-paper display 131 at a different rate and/or intensity than erasingunits 211, 212 (FIG. 7A). In one aspect, the second erasing element 364is spaced apart from the writing unit 214 by a distance D5, which may ormay not be the same as distance D3 in FIG. 7A, as the erasing element364 may deliver charges to the surface 125 of the e-paper display 131 ata different rate and/or intensity than erasing unit 212 (FIG. 7A). Ingeneral terms, the distances D4 and D5 are determined according to atleast substantially the same or according to analogous factors used todetermine distances D2 and D3 in association with at least FIGS. 4 and7A.

While not depicted in FIG. 7B, in some examples each conductive erasingelement 362, 364 may be implemented as a conductive brush or conductivewires or analogous conductive structure that maintains slidable contactwith the surface of the e-paper display 131.

In some examples, each conductive erasing element 362, 364 can take theform of a floating charge roller, such as but not limited to, suchelements disclosed in Gila et al. U.S. Pat. No. 7,050,742 issued on May23, 2006.

FIG. 8A-8C provide a series of diagrams 400 schematically representingan imaging device 410 with a multi-use erasing unit 412 separate from awriting unit 214 and by which a passive e-paper display 131 is imaged,according to one example of the present disclosure. In some examples,imaging device 410 comprises at least some of substantially the samefeatures and attributes as imaging device 210 in FIG. 7A, except forproviding a multi-use erasing unit 412 instead of two separate erasingunits 211, 212. The multi-use erasing unit 412 comprises anion-generating element which can selectably emit either positive ions ornegative ions. Accordingly, in some examples, in a state shown in FIG.8A, the erasing unit 412 emits ions 420 having a first polarity (e.g.positive in the example shown) during which relative movement occursbetween the erasing unit 412 and the entire passive e-paper display 131,as represented by directional arrow X1. This action induces the passivee-paper display 131 to switch all of it's negatively chargemicroparticles (e.g. black in one example) to the surface 125, therebygiving the surface 125 a generally uniform appearance corresponding tothe color (e.g. black) of those microparticles. In one aspect, thisaction is substantially the same as previously described in associationfor erasing unit 211 in FIG. 4.

This maneuver is followed by the passive e-paper display 131 beingreturned to a starting position relative to erasing unit 412, asrepresented per directional arrow X2 in FIG. 8B, and during which noions are emitted from erasing unit 412. In other words, erasing unit 412is in a non-emission mode during travel of e-paper display 131 in thereturn/second travel direction. As further shown in FIG. 8B, the erasingunit 412 is switched to emit ions 422 having a second polarity (e.g.negative in the example shown) during which relative movement occursbetween the erasing unit 412 and the entire passive e-paper display 131,as represented by directional arrow X1. This action induces the passivee-paper display 131 to switch all of it's positively chargemicroparticles (e.g. white in one example) to the surface 125, therebygiving the surface 125 a generally uniform appearance, such as anall-white or neutral appearance. In one aspect, this action issubstantially the same as previously described in association forerasing unit 212 in FIG. 4

Upon the passive e-paper display 131 traveling distance D6, relativemovement (as represented by arrow X1) between the e-paper display 131and the imaging device 410 continues until the writing unit 214 emitsions 424 (e.g. positive in the example shown) onto the e-paper display131 in a selectable pattern to form an image thereon as shown in FIG.8C.

As previously noted, the distance D6 corresponds to the amount of time(at least partially dependent on the relative velocity of e-paperdisplay 131) for surface charges deposited by the second action oferasing unit 412 to dissipate and for completion of the inducedmigration of microparticles to surface 125 resulting from the mostrecent erasure action. In more general terms, the distance D6 maydetermined according to at least substantially the same or according toanalogous factors used to determine distances D2 and D3 in associationwith at least FIGS. 4 and 7A. In one aspect, the distance D6 may or maynot be the same as distance D3 in FIG. 7A.

FIGS. 9A-9D provide a series of diagrams 450 schematically representingan imaging device 460 with a multi-use erasing unit 412 separate from awriting unit 214 and by which a passive e-paper display 131 is imaged,according to one example of the present disclosure. In some examples,imaging device 460 comprises at least some of substantially the samefeatures and attributes as imaging device 410 in FIGS. 8A-8C, except forproviding a multi-use erasing unit 412 being employed on more than twopasses of the e-paper display 131. In a first pass, erasing unit 412emits a blanket of negative ions 462 onto surface 125, as e-paperdisplay 131 moves in direction X1, as shown in FIG. 9A. In a secondpass, as e-paper display 131 moves in an opposite/reverse direction X2,the erasing unit 412 emits a blanket of positive ions 464 onto surface125, as shown in FIG. 9B. In a third pass as shown in FIG. 9C, e-paperdisplay 131 is moved again in direction X1 while erasing unit 412 emitsa blanket of negative ions 466 onto surface 125 to produce a generallyuniform white or neutral appearance suitable to receive a new image fromwriting unit 214.

Among other potential factors, performing multiple erasing actions suchas in the example of FIG. 9 to cycle the microparticles (120, 124)between different positions within the microcapsules (e.g. 105) in thee-paper display 131 is believed to enhance a complete erasure of surface125 of e-paper display 131. After the erasure actions are completed,writing unit 214 emits ions 468 onto surface 125 to form a new image one-paper display 131, as shown in FIG. 9D.

In some examples, distance D7 in FIG. 9A is determined according to atleast some of substantially the same factors affecting the determinationof distance D6 in FIG. 8A. In one aspect, the distance D7 may or may notbe the same as distance D6 in FIG. 8A.

FIGS. 10A-10C provide a series of diagrams 500 schematicallyrepresenting an imaging device 510 with an ion-emitting unit 514employable in an erasing mode and a writing mode, and by which a passivee-paper display 131 is imaged, according to one example of the presentdisclosure. In some examples, ion-emitting unit 514 comprises at leastsome of substantially the same features and attributes as writing unit214 (at least FIG. 4) and/or writing unit 250 (FIG. 5). However, asimplemented in imaging device 510, the ion-emitting unit 514 isselectively operated in different polarities and/or differention-emitting patterns depending on whether the unit 514 is operating inan erasing modality (e.g. 106 in FIG. 2B) or a writing modality (e.g.104 in FIG. 2B). For instance, as shown in FIG. 10A, in a first pass ofe-paper display 131 relative to unit 514, ions 520 having a firstpolarity (e.g. positive in the example shown) are emitted onto e-paperdisplay 131 to induce at least substantially the entire surface 125 tobecome populated with negatively charged microparticles, such as blackmicroparticles 124 in one example (e.g. FIG. 4).

In some examples, during this first pass the ions 520 are emitted in theform of a blanket extending across an entire width of the e-paperdisplay such that ions 520 are received onto at least substantially theentire surface 125 of e-paper display 131. In some examples, when theion-emitting unit 514 comprises a writing unit, such as writing unit 250(FIG. 5), the erasing modality is implemented by operating the set ofaddressable gates (262 in FIG. 5; 283 in FIG. 6A) in a non-selectivemode in which substantially all or all of gates (e.g. 283 in FIG. 6A)are open to permit ions to be emitted therethrough, thereby mimickingion emission from a corona, such as depicted in at least FIG. 6B.

After this action, as shown in FIG. 10B the passive e-paper display 131is returned via conveying structures 310A, 310B toward a startingposition as represented by directional arrow X2, and during which unit514 is dormant. In other words, unit 514 is in a non-emission modeduring travel of e-paper display 131 in the return/second traveldirection.

As further represented by FIG. 10B, a second pass of e-paper display 131is then initiated during which unit 514 emits second polarity ions 522(e.g. negative in the example shown) to induce at least substantiallythe entire surface 125 to become populated with positively chargedmicroparticles, such as white microparticles 120 in one example (e.g.FIG. 4). After this action, the passive e-paper display 131 is returnedtoward a starting position as represented by directional arrow X2 (FIG.10C) while unit 514 is dormant. In other words, unit 514 is in anon-emission mode during travel of e-paper display 131 in thereturn/second travel direction.

In some examples, in a manner substantially similar to that describedfor the first pass, during the second pass the ions 522 are againemitted in the form of a blanket extending across an entire width of thee-paper display 131 such that ions 522 are received onto at leastsubstantially the entire surface 125 of e-paper display 131. Aspreviously noted regarding the first pass, in some examples, during thesecond pass the ion-emitting unit 514 emits ions 522 in a non-selectivemode.

As represented by FIG. 10C, a third pass of e-paper display 131 is theninitiated during which unit 514 emits first polarity ions 524 (e.g.positive in the example shown) in a selectable pattern to induce someportions of surface 125 to become populated with positively chargedmicroparticles, such as black microparticles 124 in FIG. 4 (in oneexample), to form an image such as image 40 in FIG. 2A. In someexamples, during this third pass the ion-emitting unit 514 operates in aselective mode, such as one example of writing unit 250 in FIG. 5 (and280 in FIG. 6A) in which electrode holes are selectively activated topermit passage of ions, and thereby emit a selectable pattern of ionsonto the surface 125 of passive e-paper display 131.

As in previously described examples, the double erasing actionimplementable via unit 514 may minimize the chances of straymicroparticles (e.g. microparticle 126 in FIGS. 3A-3B) remaining atsurface 125 of e-paper display 131 prior to writing a new image via unit514.

Because the arrangement in FIGS. 10A-10C includes just one ion-emittingelement, in some examples a time period (T1) between successiveapplications (e.g. first pass, second pass, third pass) is notdetermined by a distance (e.g. D3, D4) between adjacent (but spacedapart) ion-emitting elements. Instead, the time period (T1) is at leastpartially determined according to a length of the e-paper display 131and velocity of relative movement of e-paper display 131 relative to theion-emitting unit 514. In addition, the time period (T1) is furtherdetermined according to at least some of substantially the same factorsor subject to analogous factors used to determine distances D2 and D3 inassociation with at least FIGS. 4 and 7A.

Moreover, time period (T1) between the first and second passes may ormay not be the same as the time period between the second and thirdpasses.

FIG. 11A is a block diagram schematically representing a control portion660, according to one example of the present disclosure. In someexamples, control portion 660 includes a controller 662 and a memory670. In some examples, control portion 660 provides one exampleimplementation of control portion 35 in FIG. 1B.

Controller 662 of control portion 660 can comprise at least oneprocessor 664 and associated memories that are in communication withmemory 670 to generate control signals, and/or provide storage, todirect operation of at least some components of the systems, components,and modules described throughout the present disclosure. In someexamples, these generated control signals include, but are not limitedto, employing imaging manager 671 stored in memory 670 to manage imaging(including at least erasing) a passive e-paper display in the mannerdescribed in at least some examples of the present disclosure.

In response to or based upon commands received via a user interface(e.g. user interface 690 in FIG. 11B) and/or via machine readableinstructions, controller 662 generates control signals to implement atleast timing and sequence of the operation of erasing units, writingunits, and relative movements therebetween in accordance with at leastsome examples of the present disclosure. In some examples, controller662 is embodied in a general purpose computer while in other examples,controller 662 is embodied in the imaging devices described hereingenerally or incorporated into or associated with at least some of thecomponents described throughout the present disclosure, such as controlportion 35 (FIG. 1B).

For purposes of this application, in reference to the controller 662,the term “processor” shall mean a presently developed or futuredeveloped processor (or processing resources) that executes sequences ofmachine readable instructions contained in a memory. In some examples,execution of the sequences of machine readable instructions, such asthose provided via memory 670 of control portion 660 cause the processorto perform actions, such as operating controller 662 to implement atleast erasing and/or other imaging-related functions (includingwriting), as generally described in (or consistent with) at least someexamples of the present disclosure. The machine readable instructionsmay be loaded in a random access memory (RAM) for execution by theprocessor from their stored location in a read only memory (ROM), a massstorage device, or some other persistent storage, as represented bymemory 670. In some examples, memory 670 comprises a volatile memory. Insome examples, memory 670 comprises a non-volatile memory. In someexamples, memory 670 comprises a computer readable tangible mediumproviding non-transitory storage of the machine readable instructionsexecutable by a process of controller 662. In other examples, hard wiredcircuitry may be used in place of or in combination with machinereadable instructions to implement the functions described. For example,controller 662 may be embodied as part of at least oneapplication-specific integrated circuit (ASIC). In at least someexamples, the controller 662 is not limited to any specific combinationof hardware circuitry and machine readable instructions, nor limited toany particular source for the machine readable instructions executed bythe controller 662.

In some examples, user interface 690 provides for the simultaneousdisplay, activation, and/or operation of at least some of the variouscomponents, modules, functions, parameters, features, and attributes ofcontrol portion 660 and/or the various aspects of erasing and/or writingoperations, as described throughout the present disclosure. In someexamples, at least some portions or aspects of the user interface 690are provided via a graphical user interface (GUI). In some examples,user interface 690 includes an input 692 and a display 691, which may ormay not be combined in a single element, such as a touch screen display.

FIG. 12 is a flow diagram schematically representing a method 750 ofmanufacturing an imaging device for a passive e-paper display, accordingto one example of the present disclosure. In some examples, method 750is performed via at least some of the devices, units, components,modules, elements, etc. as previously described in association with atleast FIGS. 1-11B. In some examples, method 750 is performed via atleast some devices, units, components, modules, elements, etc. otherthan previously described in association with at least FIGS. 1-11B.

As shown in FIG. 12, at 752 method 750 includes providing an erasingunit to emit ions in a first polarity followed by an opposite secondpolarity after a first time period. At 754, method 750 includesarranging a support for a passive e-paper display in a spaced apartrelationship relative to the erasing unit and by which the emitted ionsare receivable onto substantially the entire surface of the passivee-paper display. At 756, method 750 includes arranging for relativemovement to occur between the support and the erasing unit at least someof the time during the emission of ions.

Via at least some examples of the present disclosure, image clarity on apassive e-paper display may be achieved via multiple erasure actionsprior to writing a new image. Among other potential effects, multipleerasure actions may facilitate eliminating image memory from imagespreviously written to the e-paper display.

Although specific examples have been illustrated and described herein, avariety of alternate and/or equivalent implementations may besubstituted for the specific examples shown and described withoutdeparting from the scope of the present disclosure. This application isintended to cover any adaptations or variations of the specific examplesdiscussed herein. Therefore, it is intended that this disclosure belimited only by the claims and the equivalents thereof.

The invention claimed is:
 1. A device comprising: a first unitcomprising an ion generating element to emit ions in a first polaritymode followed by an opposite second polarity mode after a first timeperiod, wherein in one of the first and second polarity modes the iongenerating element is to emit negative ions and in the other respectiveone of the first and second polarity modes the ion generating element isto emit positive ions; and a support onto which a passive e-paperdisplay is mountable in a spaced apart relationship relative to thefirst unit and by which the emitted ions are receivable ontosubstantially the entire surface of the passive e-paper display, whereinthe passive e-paper display includes a layer of microcapsules, with eachmicrocapsule including a plurality of positively-charged blackmicroparticles and a plurality of negatively-charged whitemicroparticles, wherein at least the emissions of ions in the first andsecond polarity modes is to be performed without heating the passivee-paper display and separate from writing information to the passivee-paper display, wherein relative movement occurs between the supportand the first unit at least some of the time during the emission ofions.
 2. The device of claim 1, wherein the first unit includes: a firstportion to emit ions in the first polarity mode; and a second portion toemit ions in the opposite second polarity mode.
 3. The device of claim2, wherein the second portion is spaced apart from and downstream alonga travel path from, the first portion.
 4. The device of claim 1, whereinthe first unit forms part of a device comprising: a writing unit locateddownstream from the first unit and spaced apart from the support towrite a pattern of ions onto the passive e-paper display to form animage thereon, the writing unit to write the pattern of ions after asecond time period following operation of the first unit in the secondpolarity mode.
 5. The device of claim 4, wherein the writing unitincludes a plurality of addressable gates through which the ions areemitted selectively.
 6. An imager comprising: a support to releasablyreceive a passive e-paper display comprising a layer of microcapsuleswith each microcapsule including a plurality of first polarity, firstcolor microcapsules and a plurality of second polarity, second colormicrocapsules; a first unit spaced apart from the support, andcomprising a first ion generating element, to make a first contact-lessemission of first polarity ions and a second contact-less emission ofsecond polarity ions onto the passive e-paper display, wherein thesecond emission of the second polarity ions is performed a selectablefirst time period after the first emission; a second unit to make athird contact-less emission of first polarity ions, via an addressablegate array of the second unit, in a selective pattern onto the passivee-paper display to form an image, the third emission occurring aselectable second time period after the second emission with the secondunit located downstream along a travel path from the first unit; andwherein relative movement occurs between support and at least one of therespective first and second units at least some of the time during therespective first, second, and third emissions.
 7. The imager of claim 6,wherein the respective first and second emissions are to be performedwithout heating the passive e-paper display.
 8. The imager of claim 6,wherein the third emission, via the second unit, is to be performedwithout heating the passive e-paper display.
 9. The imager of claim 6,wherein the first ion generating element of the first unit comprises: afirst portion to make the first emission of first polarity ions; and asecond portion to make the second emission of second polarity ions, andwherein the second portion is located downstream along a travel pathfrom the first portion, and the second unit is spaced apart from thesecond portion downstream along the travel path.
 10. The imager of claim6, wherein the first ion generating element of the first unit is tooperate in a first polarity mode to make the first emission and in asecond opposite polarity mode to make the second emission, and wherein afirst instance of relative movement occurs during the first emissionbetween the first unit and the support and a second instance of relativemovement occurs during the second emission between the first unit andthe support.
 11. The imager of claim 10, wherein the first instance ofrelative movement is in a first relative direction and the secondinstance of the relative movement is in an opposite second relativedirection.
 12. The imager of claim 11, wherein a third instance ofrelative movement occurs during the third emission between the secondunit and the support.
 13. An imager comprising: a unit comprising anion-generating element to emit ions; a framework to support a passivee-paper display in a releasably mountable position spaced apart from,and below the unit, to receive the emitted ions in an airborne mannerwith the passive e-paper display including a layer of microcapsules,with each microcapsule including a plurality of positively-charged blackmicroparticles and a plurality of negatively-charged whitemicroparticles, wherein the unit operates in at least: an erasing modeto emit, onto the passive e-paper display, a first blanket of ionshaving a first polarity and a second blanket of ions having an oppositesecond polarity, wherein the second blanket is emitted a selectablefirst time period after the first blanket, wherein one of the first andsecond blanket of ions comprises negatively-charged ions and the otherrespective one of the first and second blanket of ions comprisespositively-charged ions, and wherein the emissions of the respectivefirst and second blanket of ions is to be performed separate fromwriting information to the passive e-paper display, wherein relativemovement occurs between the unit and the passive e-paper display atleast some of the time during operation of the erasing mode.
 14. Theimager of claim 13, wherein unit operates convertibly between theerasing mode and a writing mode, in which the writing mode is to emit,onto the passive e-paper display, a selectable pattern of ions havingthe first polarity to cause formation of an image on the passive e-paperdisplay, wherein the writing mode is implemented a selectable secondtime period after completion of the erasing mode.
 15. The imager ofclaim 14, wherein the unit includes a plurality of addressable gatesthrough which the ions are emitted, and in the erasing mode, at leastsubstantially all of the gates are open to permit emission of therespective first and second blanket of ions.
 16. The imager of claim 15,wherein in the writing mode, selectable gates are open to permitemission of the selectable pattern of ions.
 17. The imager of claim 14,comprising: a controller to cause relative movement, via the framework,of the e-paper display in: a first travel direction during emission ofthe respective first and second blanket of ions in the erasing mode andduring the writing mode; and an opposite second direction during anon-emission mode occurring between the first and second emission ofions in the erasing mode and during a non-emission mode occurringbetween the second emissions of ions in the erasing mode and the writingmode.